Cooper is the second person sentenced in connection with the case. Jarbari Pea pleaded guilty to charges stemming from the case in 2017.

Covington police were called to the Columbia Street landing on March 13, 2016, to investigate a case in which two teens had smoked synthetic marijuana called "Mojo'' and passed out. One of the teens, Alexander James Shelby, 17, was pronounced dead at an area hospital, authorities said.

Police said Cooper provided the mojo to Pea, 25, of Covington, who in turn sold it to the teens. Pea and Cooper each made $10 from the transaction, Montgomery’s office said. Cooper and Pea both were initially accused of second-degree murder.

Pea pleaded guilty in March 2017 to negligent homicide and distribution of synthetic marijuana. The DA’s office said he was sentenced to five years on the negligent homicide count and 10 years, with five suspended, on the distribution count. Those sentences are to run concurrently, the DA’s office said.

The DA’s office said state District Judge Scott Gardner sentenced Cooper as a second felony offender to five years on the negligent homicide plea and 30 years on the distribution plea. The sentences will be served concurrently, the DA’s office said.

Montgomery, in the news release, said it’s easy to underestimate the dangers of illegal drugs. The synthetic drugs have chemicals that react unpredictably in people, he said.